Unless carefully removed and protected, dissolved gas will generally accumulate in a fluid. Once a gas is dissolved in a fluid the dissolved gas can have various undesirable effects. For example in hydraulic systems, dissolved gas in the hydraulic fluid can cause reduced control stiffness. Dissolved gas may also damage equipment, or pose as a serious safety concern in hydraulic systems as well as other systems. Dissolved gas can cause cavitations, which severely damage system components, as well as cause localized degradation. Dissolved gas can aid corrosion damaging equipment, for example by providing oxygen to the bare metal of a pipe, pump or valve. Inadvertently dissolved gases may pose as a danger to equipment, the environment, or people. For example, Carbon-Monoxide dissolved in a liquid methane fuel cell system may poison a subsequent fuel cell.
Unfortunately, dissolved gas in a fluid is difficult to detect. Current systems employ a cylinder to compress and decompress the fluid, freeing the dissolved air and generating trapped air. The generated trapped air is subsequently detected by various techniques. Unfortunately, this method is slow since each sample must be tediously compressed and decompressed by the cylinder. Furthermore, this method cannot be used in-situ, since the fluid flow through the cylinder must be blocked during compression/decompression of the cylinder. The cylinder may alternately be connected in parallel to a fluid flow, however only a small representative sample can be processed at a time, limiting the accuracy of the detection of dissolved gases in heterogeneous fluids.
Therefore, there is a need for the real-time detection of dissolved gas in a fluid that can be implemented in-situ without requiring the extraction of sample fluids. It is desired to have a system whereby a sensor can be implemented in-line with the flow of the fluid in a manner that allows continuous readings of the dissolved air in the fluid as it passes through the system.